TAMPA -- Lisa Cook took a few extra moments to hug and kiss her husband, Chris, at the front door before she left for work Thursday. It was the 20th anniversary of their first date.

"We moved in together that same day," Chris Cook said.

Minutes later, Mrs. Cook had cause to wonder whether the extended goodbye might have been seconds that saved her life.

About 7:30 a.m., she was southbound on the Veterans Expressway, driving about 60 mph behind a Ford pickup. Suddenly, she saw debris and a truck axle rolling toward her.

A propane gas tanker had veered out of the northbound lanes, crossed the grass median and slammed into the pickup in front of Lisa Cook. Then, in a scene that seemed to belong in a Hollywood action movie and not in everyday life, the body of the propane tanker ripped away from its axles, hurtled over the expressway wall and plunged onto an entry ramp at Ehrlich Road.

Cook swerved her Mercury Marquis to the left, skidded to a stop, jumped out and headed for the wreckage. Two men lifted out the driver of the Ford pickup, 44-year-old Nancy J. Smolsky of New Port Richey, and laid her down on the ground.

Cook put a towel under the head of the grievously injured woman and tried to comfort her.

"I was touching her shoulders, holding her hands and letting her know help was on the way," Cook said later.

Smolsky, who was on her way to federal jury duty in downtown Tampa, died at the scene. The driver of the propane truck, Ronald C. Pugh, 63, of Tampa, was killed instantly.

Miraculously, no other drivers were injured. Thousands of northwest Hillsborough County commuters pass through the Ehrlich Road intersection each morning.

And just as miraculously, the 2,600 pounds of propane in the gas tanker did not explode. A small fire broke out but was quickly extinguished.

Three miles of the expressway -- from the Gunn Highway exit to the Hutchison Road exit -- were closed in both directions for much of the day. Firefighters and emergency response workers spent hours draining the propane gas out of the truck, said Ray Yeakley, public information officer for Hillsborough County Fire Rescue.

Motorists struggled to find alternative routes south and north. Traffic detoured off the expressway backed up along two-lane rural roads like Hutchison, many of the drivers out-of-staters searching desperately to find their bearings.

The expressway's northbound lanes were reopened in the afternoon. It wasn't until shortly after 7 p.m. -- nearly 12 hours after the accident -- that the southbound lanes were opened to traffic.

Traffic investigators said they did not have an explanation for why Pugh's propane tanker veered out of the northbound lanes.

"Fortunately we did not have that much traffic around because it could have been a lot worse," said Lt. Sterling King of the Florida Highway Patrol.

The Veterans Expressway has only intermittent barriers to prevent cars crossing into oncoming lanes. The gas tanker veered through the median just before such a barrier.

Some residents in Woodbriar West, a nearby subdivision, were told to leave their homes because of concern that the propane gas could ignite.

"It was just a loud explosion," said Jose Fernandez, a Woodbriar West resident. "We were up, having breakfast and getting the kids ready for school. I thought it was a small aircraft that had crashed."

People who answered the door at Pugh's home declined to speak to a reporter, referring all questions to the propane company, Bay Cities Gas. Managers there closed the Tampa office after the crash and did not return telephone messages.

Pugh's driving record showed one minor infraction. In July 2000, he was found guilty in Hillsborough County Court of failing to obey a traffic signal. The judge withheld adjudication.

The tanker crash was the second accident involving a Bay Cities truck in recent months. Four months ago, a Bay Cities driver was severely burned and his truck destroyed when leaking gas caught fire on a street in New Tampa.

Les Grove, area director of the Occupational Safety and Health Administration, said the agency has never investigated Bay Cities Gas.

Nancy Smolsky's friends and family members said she worked as a customer service representative for Allied Vaughn, a company that duplicates CDs and videotapes. She drove the Veterans Expressway every day and was well-known by toll workers, said her friend Cathy Schroder.

"They would know her on sight and it was always because of her smile," Schroder said.

Smolsky shared a renovated house on Cumber Drive in New Port Richey with her sister, Patty Smolsky, and Schroder.

They said Nancy Smolsky's biggest concern when she left home Thursday morning was that she would get out of federal court in time to hand out candy to trick or treaters.

Nancy Smolsky, who moved to Florida seven years ago from New Jersey, loved horses and NASCAR and had adopted two stray mutts, named Pooh and Shakespeare. She supported causes ranging from the developmentally disabled to animal rights, her sister said.

For Lisa Cook, a consultant who works for IBM, the day was one of confronting tragedy and counting blessings.

"I've never seen anyone die," she said. "I couldn't believe I was walking around when the other two people were dead.